Clinical study of Thai patients with ankylosing spondylitis.

Sixty-one Thai patients with ankylosing spondylitis (AS), diagnosed in accordance with Rome and New York criteria for AS, were studied. The cases includes idiopathic AS (46 cases), Reiter's syndrome AS (8 cases) and psoriatic spondylitis (7 cases). The vast majority of patients were male (Male:Female = 11.2:1), and in over three-fourths the age of onset was between 10 and 39. Low back pain and peripheral arthritis as the initial manifestations were observed in 78.68 and 55.73% of patients respectively. Peripheral arthritis was evident during the course of illness in 72.13% of cases, oligoarticular arthritis being predominant (68.97%). Heel pain, tendonitis and plantar pain were noted in 19.67, 4.92 and 3.28% respectively. Most patients had lumbosacral and thoracic spine involvements, and only 49.18% showed involvement of the cervical spine. Bilateral sacroiliitis was noted in 98.36%. Uveitis was evident in 11.47% while evidence of aortic insufficiency was noted in 3.28%. An association with HLA-B27 was encountered in 91.07% of all cases. In general, the clinical features of AS in Thai patients are similar to those reported elsewhere, but an association with inflammatory bowel disease and Behcet's disease are notably absent.